Polyamide

ABSTRACT

A process for the preparation of novel polyamides, the use of such polyamides for the production of fibers, sheets and moldings, and fibers, sheets and moldings obtainable from such polyamides, are provided.

The present invention relates to a process for the preparation ofpolyamides (VIII) obtainable from monomers (I) selected from the groupconsisting of lactams, ω-aminocarboxylic acids, ω-aminocarboxylic acidnitrites, ω-aminocarboxamides, ω-aminocarboxylic acid salts,ω-aminocarboxylic acid esters, equimolar mixtures of diamines anddicarboxylic acids, dicarboxylic acid/diamine salts, dinitriles anddiamines, or mixtures of such monomers, wherein the polymerization ofthe monomers (I) is carried out in the presence of

(II) 0.01 to 0.5% by weight of a sterically hindered piperidinederivative which has a functional group capable of amide formation withrespect to the polyamide (VIII),

(III) 0.01 to 0.5% by weight of a compound which has several aminegroups capable of amide formation with respect to the polyamide (VIII),

and optionally a compound selected from the group consisting of

a compound (IV) which has an amine group capable of amide formation withrespect to the polymer main chain of the polyamide (VIII),

a compound (V) which has a carboxylic acid group capable of amideformation with respect to the polymer main chain of the polyamide(VIII),

and a compound (VI), different from the monomer (I), which has severalcarboxylic acid groups capable of amide formation with respect to thepolymer main chain of the polyamide (VIII),

or mixtures thereof,

the amounts of (I), (II), (III), (IV), (V) and (VI) adding up to 100%,the components (II), (III), (IV), (V) and (VI) being bonded to thepolymer chain via amide linkages, and the sum of the amine groups of thecomponents (II), (III) and (IV) capable of amide formation with respectto the polymer chain being greater than or equal to the sum of thecarboxylic acid groups of the components (II), (V) and (VI) capable ofamide formation with respect to the polymer chain.

The invention further relates to polyamides obtainable by this process,to the use of such polyamides for the production of fibers, textilefabrics and moldings, and to fibers, textile fabrics and moldingsobtainable from such polyamides.

TECNICAL FIELD BACKGROUND ART

The use of polyamides for the production of fibers and yarns isgenerally known, for example from: Ullmann's Encyclopedia of IndustrialChemistry, 5th ed., vol. A10 , VCH Verlagsgesellschaft mbH, Weinheim,Germany, 1987, pages 567-579.

Yarns are produced in a manner known per se by melting the polyamide,spinning it into a fiber and stretching, texturing and optionallyaftertreating said fiber. This can be followed by cabling and heatsetting of the yarn.

Setting processes are known per se, an example being the heat-setprocess from Hödrauf-Suessen, Germany.

An essential step of setting is the passage of the yarn through aclimatic chamber under defined process conditions such as the residencetime of the yarn and the temperature and relative humidity of theatmosphere in the climatic chamber.

The disadvantage here is that the quality, for example the APHA (Hazen)index according to European standard EN 1557 (corresponding to USstandard ASTM D1003) and the relative viscosity of yarns from polyamidesknown per se, is markedly impaired during this setting. The drop inrelative viscosity and the rise in APHA index indicate that the polymerhas been degraded, i.e. damaged.

DISCLOUSURE OF INVENTION

It is an object of the present invention to provide polyamides which canbe used to produce fibers, sheets or moldings, especially yarns, whichdo not exhibit said disadvantages, as well as processes which enablesuch polyamides to be prepared in a technically simple and economicmanner.

We have found that this object is achieved by the process defined at theoutset, polyamides obtainable by such a process, the polyamides definedat the outset, the use of such polyamides for the production of fibers,textile fabrics and moldings, and fibers, textile fabrics and moldingsobtainable from such polyamides.

Polyamides are understood as meaning homopolymers, copolymers, mixturesand grafts of synthetic long-chain polyamides in which the essentialconstituent is recurring amide groups in the polymer main chain.Examples of such polyamides are nylon 6 (polycaprolactam), nylon 6,6(polyhexamethylene adipamide), nylon 4,6 (polytetramethylene adipamide),nylon 6,10 (polyhexamethylene sebacamide), nylon 6,12 (polyhexamethylenedecane-1,10-dicarboxamide), nylon 7 (polyenantholactam), nylon 11(polyundecanolactam) and nylon 12 (polydodecanolactam). These polyamidesare known to have the generic name nylon. Polyamides are also understoodas meaning the so-called aramides (aromatic polyamides) such aspolymetaphenylene isophthalamide (NOMEX® fiber, U.S. application Ser.No. 3,287,324) or polyparaphenylene terephthalamide (KEVLAR® fiber, U.S.application Ser. No. 3,671,542).

In principle, polyamides can be prepared by two processes.

In the polymerization of dicarboxylic acids and diamines, and in thepolymerization of amino acids or derivatives thereof such asaminocarboxylic acid nitriles, aminocarboxamides, aminocarboxylic acidesters or aminocarboxylic acid salts, the amino and carboxyl end groupsof the starting monomers or starting oligomers react with one another toform an amide group and water. The water can then be removed from thepolymer mass. In the polymerization of carboxamides, the amino and amideend groups of the starting monomers or starting oligomers react with oneanother to form an amide group and ammonia. The ammonia can then beremoved from the polymer mass. This polymerization reaction isconventionally referred to as polycondensation.

The polymerization of lactams as starting monomers or starting oligomersis conventionally referred to as polyaddition.

MODE(S) FOR CARRYING OUT THE INVENTION

According to the invention, monomers (I), selected from the groupconsisting of lactams, (ω-aminocarboxylic acids, ω-aminocarboxylic acidnitriles, (ω-aminocarboxamides, ω-aminocarboxylic acid salts,ω-aminocarboxylic acid esters, equimolar mixtures of diamines anddicarboxylic acids, dicarboxylic acid/diamine salts, dinitriles anddiamines, or mixtures of such monomers, are used.

Suitable monomers (I) are

monomers or oligomers of a C₂ to C₂₀, preferably C₂ to C₁₈,arylaliphatic or, preferably, aliphatic lactam such as enantholactam,undecanolactam, dodecanolactam or caprolactam,

monomers or oligomers of C₂ to C₂₀, preferably C₃ to C₁₈,aminocarboxylic acids such as 6-aminohexanoic acid or 11-aminoundecanoicacid, dimers, trimers, tetramers, pentamers or

hexamers thereof, and salts thereof such as alkali metal salts, forexample lithium, sodium or potassium salts,

C₂ to C₂₀, preferably C₃ to C₁₈, aminocarboxylic acid nitriles such as6-aminohexanoic acid nitrile or 11-aminoundecanoic acid nitrile,

monomers or oligomers of C₂ to C₂₀ amino acid amides such as6-aminohexanamide or 11-aminoundecanamide, and dimers, trimers,tetramers, pentamers or hexamers thereof,

esters, preferably C₁-C₄ alkyl esters, such as methyl, ethyl, n-propyl,i-propyl, n-butyl, i-butyl or s-butyl esters, of C₂ to C₂₀, preferablyC₃ to C₁₈, aminocarboxylic acids, such as 6-aminohexanoic acid esters,for example methyl 6-aminohexanoate, or 11-aminoundecanoic acid esters,for example methyl 11-aminoundecanoate,

monomers or oligomers of a C₂ to C₂₀ , preferably C₂ to C₁₂,alkyldiamine, such as tetramethylenediamine or, preferably,hexamethylenediamine,

with a C₂ to C₂₀, preferably C₂ to C₁₄, aliphatic dicarboxylic acid ormono- or dinitriles thereof, such as sebacic acid, decanedicarboxylicacid, adipic acid, sebacic acid dinitrile, decanoic acid dinitrile oradipodinitrile,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

monomers or oligomers of a C₂ to C₂₀, preferably C₂ to C₁₂,alkyldiamine, such as tetramethylenediamine or, preferably,hexamethylenediamine,

with a C_(8 l to C) ₂₀, preferably C₈ to C₁₂, aromatic dicarboxylic acidor derivatives thereof, for example chlorides, such asnaphthalene-2,6-dicarboxylic acid or, preferably, isophthalic acid orterephthalic acid,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

monomers or oligomers of a C₂ to C₂₀, preferably C₂ to C₁₂,alkyldiamine, such as tetramethylenediamine or, preferably,hexamethylenediamine,

with a C₉ to C₂₀, preferably C₉ to C₁₈, arylaliphatic dicarboxylic acidor derivatives thereof, for example chlorides, such as o-, m- orp-phenylenediacetic acid,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

monomers or oligomers of a C₆ to C₂₀, preferably C₆ to C₁₀, aromaticdiamine, such as m- or p-phenylenediamine,

with a C₂ to C₂₀, preferably C₂ to C₁₄, aliphatic dicarboxylic acid ormono- or dinitriles thereof, such as sebacic acid, decanedicarboxylicacid, adipic acid, sebacic acid dinitrile, decanoic acid dinitrile oradipodinitrile,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

monomers or oligomers of a C₆ to C26, preferably C₆ to C₁₀, aromaticdiamine, such as m- or p-phenylenediamine,

with a C₂ to C₂₀, preferably C₂ to C₁₂, aromatic dicarboxylic acid orderivatives thereof, for example chlorides, such asnaphthalene-2,6-dicarboxylic acid or, preferably, isophthalic acid orterephthalic acid,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

monomers or oligomers of a C₆ to C₂₀, preferably C₆ to C₁₀, aromaticdiamine, such as m- or p-phenylenediamine,

with a C₉ to C₂₀, preferably C₉ to C₁₀, arylaliphatic dicarboxylic acidor derivatives thereof, for example chlorides, such as o-, m- orp-phenylenediacetic acid,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

monomers or oligomers of a C₇ to C₂₀, preferably C₈ to C₁₈,arylaliphatic diamine, such as m- or p-xylylenediamine,

with a C₂ to C₂₀, preferably C₂ to C₁₄, aliphatic dicarboxylic acid ormono- or dinitriles thereof, such as sebacic acid, decanedicarboxylicacid, adipic acid, sebacic acid dinitrile, decanoic acid dinitrile oradipodinitrile,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

monomers or oligomers of a C₇ to C₂₀, preferably C₈ to C₁₈,arylaliphatic diamine, such as m- or p-xylylenediamine,

with a C₆ to C₂₀, preferably C₆ to C₁₀, aromatic dicarboxylic acid orderivatives thereof, for example chlorides, such asnaphthalene-2,6-dicarboxylic acid or, preferably, isophthalic acid orterephthalic acid,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

monomers or oligomers of a C₇ to C₂₀, preferably C₈ to C₁₈,arylaliphatic diamine, such as m- or p-xylylenediamine,

with a C₆ to C20, preferably C₆ to C₁₁, arylaliphatic dicarboxylic acidor derivatives thereof, for example chlorides, such as o-, m- orp-phenylenediacetic acid,

and dimers, trimers, tetramers, pentamers or hexamers thereof,

and homopolymers, copolymers, mixtures and grafts of such startingmonomers or starting oligomers.

Preferred starting monomers or starting oligomers are those whichpolymerize to yield the polyamides nylon 6, nylon 6,6, nylon 4,6, nylon6,10, nylon 7, nylon 11, nylon 12 and the aramides polymetaphenyleneisophthalamide or polyparaphenylene terephthalamide, especially nylon 6and nylon 6,6.

Unless indicated otherwise, the proportions by weight indicated for thecompounds (II), (III), (IV), (V) and (VI) are based on the amount ofmonomer (I) used.

According to the invention, the polymerization of the monomer (I) iscarried out in the presence of a sterically hindered piperidinederivative (II) which has a group capable of amide formation withrespect to the polymer main chain of the polyamide (VIII), or mixturesthereof.

Suitable compounds (II) are preferably those of the formula

in which

R¹ is a functional group capable of amide formation with respect to thepolymer main chain of the polyamide (VIII),

preferably a group —(NH)R⁵, in which R⁵ is hydrogen or C₁-C₈ alkyl, or acarboxyl group, or a carboxyl derivative, or a group —(CH₂)_(x)(NH)R⁵,in which X is 1 to 6 and R⁵ is hydrogen or C₁-C₈ alkyl, or a group—(CH₂)_(y)COOH, in which Y is 1 to 6, or a —(CH₂)_(y)COOH acidderivative, in which Y is 1 to 6,

especially a group —NH₂,

R² is an alkyl group, preferably a C₁-C₄ alkyl group such as methyl,ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, s-butyl, [sic]

especially a methyl group, and R³ is hydrogen, C₁-C₄ alkyl or O—R⁴, inwhich R⁴ is hydrogen or C₁-C₇ alkyl,

R³ being hydrogen in particular.

In such compounds, steric hindrance usually prevents the tertiary aminogroups, and especially the secondary amino groups, of the piperidinering systems from reacting.

A particularly preferred compound (II) is 304-amino-2,2,6,6-tetramethylpiperidine.

According to the invention, the compound (II) is used in amounts of atleast 0.01% by weight, preferably of at least 0.05% by weight andparticularly preferably of at least 0.1% by weight.

According to the invention, the compound (II) is used in amounts of atmost 0.5% by weight, preferably of at most 0.3% by weight andparticularly preferably of at most 0.2% by weight.

According to the invention, the polymerization of the monomer (I) iscarried out in the presence of a compound (III) which has several, suchas two, three or four, preferably two, amino groups capable of amideformation with respect to the polymer main chain of the polyamide(VIII), or mixtures thereof. Suitable compounds (III) are advantageouslyC₂ to C₂₀, preferably C₂ to C₁₂, alkyldiamines such astetramethylenediamine or, preferably, hexamethylenediamine, C₆ to C₂₀,preferably C₆ to C₁₀, aromatic diamines such as m- orp-phenylenediamine, or C₇ to C₂₀, preferably C₈ to C18, arylaliphaticdiamines such as m- or p-xylylenediamine, or those compounds which areconventionally used as chain regulators in the polymerization of themonomer (I). Hexamethylenediamine is particularly preferred.

Such compounds (III) can carry substituents such as halogens, forexample fluorine, chlorine or bromine, sulfonic acid groups, or saltsthereof such as lithium, sodium or potassium salts, or they can beunsubstituted.

According to the invention, the compound (III) is used in amounts of atleast 0.01% by weight, preferably of at least 0.05% by weight andparticularly preferably of at least 0.2% by weight.

According to the invention, the compound (III) is used in amounts of atmost 0.5% by weight, preferably of at most 0.35% by weight andparticularly preferably of at most 0.25% by weight.

According to the invention, the polymerization of the monomer (I) isoptionally carried out in the presence of a compound (IV) which has anamino group capable of amide formation with respect to the polymer mainchain of the polyamide (VIII), or mixtures thereof.

Suitable compounds (IV) are advantageously C₂ to C₂₀, preferably C₂ toC₁₂, alkylamines such as cyclohexylamine, C₆ to C₂₀, preferably C₆ toC₁₀, aromatic monoamines such as aniline, or C₇ to C₂₀, preferably C₈ toC₁₈, arylaliphatic monoamines such as benzylamine, or those compoundswhich are conventionally used as chain regulators in the polymerizationof the monomer (I).

Such compounds (IV) can carry substituents such as halogens, for examplefluorine, chlorine or bromine, sulfonic acid groups, or salts thereofsuch as lithium, sodium or potassium salts, or they can beunsubstituted.

The compound (IV) can advantageously be used in amounts of 0 to 0.5% byweight, preferably of 0 to 0.35% by weight and particularly preferablyof 0 to 0.25% by weight.

According to the invention, the polymerization of the monomer (I) isoptionally carried out in the presence of a compound (V) which has acarboxylic acid group capable of amide formation with respect to thepolymer main chain of the polyamide (VIII), or mixtures thereof.

Suitable compounds (V) are advantageously C₂ to C₂, preferably C₂ toC₁₂, carboxylic acids such as acetic acid or propionic acid, C₇ to C₂₁,preferably C₇ to C₁₁, aromatic carboxylic acids such as benzoic acid, orC₈ to C₂₁, preferably C₉ to C₁₉, arylaliphatic carboxylic acids, orthose compounds which are conventionally used e.g. as chain regulatorsin the polymerization of the monomer (I).

Such compounds (V) can carry substituents such as halogens, for examplefluorine, chlorine or bromine, sulfonic acid groups, or salts thereofsuch as lithium, sodium or potassium salts, or they can beunsubstituted.

The compound (V) can advantageously be used in amounts of 0 to 0.5% byweight, preferably of 0 to 0.35% by weight and particularly preferablyof 0 to 0.25% by weight.

According to the invention, the polymerization of the monomer (I) isoptionally carried out in the presence of a compound (VI), differentfrom the monomer (I), which has several, such as two, three or four,preferably two, carboxylic acid groups capable of amide formation withrespect to the polymer main chain of the polyamide (VIII), or mixturesthereof.

Suitable compounds (VI) are advantageously C₂ to C₂₀, preferably C₂ toC₁₂, dicarboxylic acids such as sebacic acid, dodecanoic acid,cyclohexane-1,4-dicarboxylic acid or, preferably, adipic acid, C₈ toC₂₂, preferably C₈ to C₁₂, aromatic dicarboxylic acids such as benzene-and naphthalenedicarboxylic acids, preferablynaphthalene-2,6-dicarboxylic acid, isophthalic acid or terephthalicacid, or C₉ to C₂₂, preferably C₉ to C₂₀, arylaliphatic dicarboxylicacids, or those compounds which are conventionally used as chainregulators in the polymerization of the monomer (I). Terephthalic acidand isophthalic acid are particularly preferred.

Such compounds (VI) can carry substituents such as halogens, for examplefluorine, chlorine or bromine, sulfonic acid groups, or salts thereofsuch as lithium, sodium or potassium salts, or they can beunsubstituted.

Preferred compounds (VI) are sulfonated dicarboxylic acids, especiallysulfoisophthalic acid, and one of its salts such as its alkali metalsalts, for example the lithium, sodium or potassium salt, preferably thelithium or sodium salt and particularly preferably the lithium salt.

The compound (VI) can advantageously be used in amounts of 0 to 0.5% byweight, preferably of 0 to 0.35% by weight and particularly preferablyof 0 to 0.25% by weight.

Particularly advantageously, the compound (VI) can be used in amountssuch that the molar amount of the carboxylic acid groups of the compound(VI) capable of amide formation with respect to the polymer main chainof the polyamide (VIII) is less than the molar amount of the aminegroups of the compound (III) capable of amide formation with respect tothe polymer main chain of the polyamide (VIII).

According to the invention, the amounts of (I), (II), (III), (IV), (V)and (VI) add up to 100%.

According to the invention, the components (II), (III), (IV), (V) and(VI) are bonded to the polymer chain via amide linkages.

According to the invention, the sum of the amine groups of thecomponents (II), (III) and (IV) capable of amide formation with respectto the polymer chain is greater than or equal to, preferably greaterthan, the sum of the carboxylic acid groups of the components (II), (V)and (VI) capable of amide formation with respect to the polymer chain.

The compounds of formulae (II), (III), (IV), (V) and (VI) can be addedto the starting monomers (I) or the polymerizing reaction mixture andcan be bonded to the polymer main chain of the polyamide by reaction ofat least one of the amide-forming groups.

The process according to the invention yields polyamides with theadvantageous properties mentioned at the outset.

The polymerization or polycondensation of the starting monomers (I) inthe presence of the compounds (II), (III), (IV), (V) and (VI) ispreferably carried out by the conventional processes. Thus thepolymerization of caprolactam as the monomer (I) in the presence of(II), (III), (IV), (V) and (VI) can be carried out for example by thecontinuous or batch processes described in DE-A 14 95 198, DE-A 25 58480, DE-A 44 13 177, Polymerization Processes, Interscience, New York,1977, pp. 424-467, and Handbuch der Technischen Polymerchemie (Handbookof Industrial Polymer Chemistry), VCH Verlagsgesellschaft, Weinheim,1993, pp. 546-554. The polymerization of AH salt as (I) in the presenceof (II), (III), (IV), (V) and (VI) can be carried out by theconventional batch process (cf.: Polymerization Processes, Interscience,New York, 1977, pp. 424-467, especially 444-446) or by a continuousprocess, e.g. according to EP-A 129 196. In principle, (II), (III),(IV), (V), (VI) and the starting monomers (I) can be fed into thereactor separately or as a mixture.

In another preferred embodiment, the polymerization or polycondensationby the process according to the invention is carried out in the presenceof at least one pigment. Preferred pigments are titanium dioxide,preferably in the form of the anatase modification, or colorizingcompounds of an inorganic or organic nature. The pigments are preferablyadded in an amount of 0 to 5 parts by weight, especially of 0.02 to 2parts by weight, based in each case on 100 parts by weight of polyamide.The pigments can be fed into the reactor with the starting materials orseparately therefrom. The use of (II), (III), (IV), (V) and (VI)(including as chain regulator constituent) markedly improves theproperties of the polymer compared with a polymer which contains onlypigment and no compounds (II), (III), (IV), (V) and (VI), or onlypigment and a combination of compounds (II), (III), (IV), (V) and (VI)falling outside the process defined at the outset.

The polyamides according to the invention can advantageously be used forthe production of threads, fibers, sheets, textile fabrics and moldings.Threads obtained from polyamides, especially polycaprolactam, by fastspinning at drawing-off speeds of at least 4 000 m/min are particularlyadvantageous. The threads, fibers, sheets, textile fabrics and moldingsobtained using the polyamides according to the invention can have avariety of uses, for example as textile clothing or carpet fibers.

EXAMPLES

Heat setting was carried out by the Hörauf-Suessen heat-set process on aGVA 5000 yarn finishing unit with the following parameters:

thread count: 6

temperature: 190-200° C.

residence time:40-60 seconds

dew point: 88-98° C.

The APHA index was determined according to European standard EN 1557against a Pt-Co standard.

The relative viscosity was determined by weighing 500 mg of the sampleinto a 50 ml volumetric flask and making up to the mark with 96% byweight sulfuric acid. The sample was dissolved to give a homogeneoussolution.

In an Ubbelohde No. II viscometer, the flow time between the upper andlower calibration marks was determined at 25° C. ±0.05° C. Themeasurements were repeated until three successive measurements fellwithin a 0.3 second range. The flow time was determined for the solventin the same way. The relative viscosity (RV) was determined according to

RV=T/T ₀

where: T: flow time of solution

T₀: To flow time of solvent

The amounts indicated in the Examples for the compounds TAD, HMD and TPAare in % by weight based on (I).

Comparison Examples 1-2, Example 1

Yarns were prepared from caprolactam as the monomer (I) with thecompositions shown in Table 1 and the APHA values were determined beforeand after heat setting.

TABLE 1 APHA APHA RV RV before after before after TAD HMD TPA settingsetting setting setting Comp. 0.12 — 0.33 11 66 2.84 2.75 Ex. 1 Comp. —0.32 — 27 45 2.75 2.72 Ex. 2 Ex. 1 0.16 0.22 — 13 27 2.79 2.79

TAD: 4-amino-2,2,6,6-tetramethylpiperidine

HMD: hexamethylenediamine

TPA: terephthalic acid

We claim:
 1. A process for the preparation of polyamides (VIII)obtainable from monomers (I) selected from the group consisting oflactams, ω-aminocarboxylic acids, ω-aminocarboxylic acid ni-triles,ω-aminocarboxamides, ω-aminocarboxylic acid salts, ω-ami-nocarboxylicacid esters, equimolar mixtures of diamines and di-carboxylic acids,dicarboxylic acid/diamine salts, dinitriles and diamines, or mixtures ofsuch monomers, wherein the polymerization of the monomers (I) is carriedout in the presence of (II) 0.01 to 0.5% by weight of a stericallyhindered piperidine derivative which has a functional group capable ofamide formation with respect to the polymer main chain of the polyamide(VIII), (III) 0.01 to 0.5% by weight of a compound which has severalamine groups capable of amide formation with respect to the polymer mainchain of the polyamide (VIII), and optionally a compound selected fromthe group consisting of a compound (IV) which has an amine group capableof amide formation with respect to the polymer main chain of thepolyamide (VIII), a compound (V) which has a carboxylic acid groupcapable of amide formation with respect to the polymer main chain of thepolyamide (VIII), and a compound (VI), different from the monomer (I),which has several carboxylic acid groups capable of amide formation withrespect to the polymer main chain of the polyamide (VIII), or mixturesthereof, the amounts of (I), (II), (III), (IV), (V) and (VI) adding upto 100%, the components (II), (III), (IV), (V) and (VI) being bonded tothe polymer chain via amide linkages, and the sum of the amine groups ofthe components (II), (III) and (IV) capable of amide formation withrespect to the polymer chain being greater than or equal to the sum ofthe carboxylic acid groups of the components (II), (V) and (VI) capableof amide formation with respect to the polymer chain.
 2. A process asclaimed in claim 1 wherein the compound (III) has two amine groupscapable of amide formation with respect to the polyamide (VIII).
 3. Aprocess as claimed in claim 1 wherein hexamethylenediamine is used asthe compound (III).
 4. A process as claimed in claim 1 wherein4-amino-2,2,6,6-tetramethylpiperidine is used as the compound (II).
 5. Aprocess as claimed in claim 1 wherein the compound (VI) has twocarboxylic acid groups capable of amide formation with respect to thepolyamide (VIII).
 6. A process as claimed in claim 1 wherein asulfonated dicarboxylic acid is used as the compound (VI).
 7. A processas claimed in claim 1 wherein sulfoisophthalic acid or one of its saltsis used as the compound (VI).
 8. A polyamide (VIII) obtainable by aprocess as claimed in claim
 1. 9. A fiber obtainable from a polyamide(VIII) as claimed in claim
 9. 10. A textile fabric obtainable from apolyamide (VIII) as claimed in claim
 8. 11. A molding obtainable from apolyamide (VIII) as claimed in claim 8.